Electrical monitoring of polyelectrolyte multilayer formation by means of capacitive field-effect devices
- The semiconductor field-effect platform represents a powerful tool for detecting the adsorption and binding of charged macromolecules with direct electrical readout. In this work, a capacitive electrolyte–insulator–semiconductor (EIS) field-effect sensor consisting of an Al-p-Si-SiO2 structure has been applied for real-time in situ electrical monitoring of the layer-by-layer formation of polyelectrolyte (PE) multilayers (PEM). The PEMs were deposited directly onto the SiO2 surface without any precursor layer or drying procedures. Anionic poly(sodium 4-styrene sulfonate) and cationic weak polyelectrolyte poly(allylamine hydrochloride) have been chosen as a model system. The effect of the ionic strength of the solution, polyelectrolyte concentration, number and polarity of the PE layers on the characteristics of the PEM-modified EIS sensors have been studied by means of capacitance–voltage and constant-capacitance methods. In addition, the thickness, surface morphology, roughness and wettabilityof the PE mono- and multilayers have been characterised by ellipsometry, atomic force microscopy and water contact-angle methods, respectively. To explain potential oscillations on the gate surface and signal behaviour of the capacitive field-effect EIS sensor modified with a PEM, a simplified electrostatic model that takes into account the reduced electrostatic screening of PE charges by mobile ions within the PEM has been proposed and discussed.
Author: | Arshak PoghossianORCiD, M. Weil, A. G. Cherstvy, Michael Josef SchöningORCiD |
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DOI: | https://doi.org/10.1007/s00216-013-6951-9 |
ISSN: | 1432-1130 ; 1618-2642 |
Parent Title (English): | Analytical and bioanalytical chemistry |
Publisher: | Springer |
Place of publication: | Berlin |
Document Type: | Article |
Language: | English |
Year of Completion: | 2013 |
Volume: | 405 |
Issue: | 20 |
First Page: | 6425 |
Last Page: | 6436 |
Link: | https://doi.org/10.1007/s00216-013-6951-9 |
Zugriffsart: | campus |
Institutes: | FH Aachen / Fachbereich Medizintechnik und Technomathematik |
FH Aachen / INB - Institut für Nano- und Biotechnologien | |
collections: | Verlag / Springer |